Digital photography and other digital media have replaced a major segment of traditional analog media. This raises the question of how to authenticate or verify that the digitally taken photograph or other digital media has not been tampered with or altered. Digital data can be easily duplicated or altered utilizing computers and other digital devices. So many software applications are available for video or audio processing that for even a relatively unskilled person can easily alter digitally captured data. Thus, persons relying on a digital photograph or other digital data for factual accuracy may want proof that the digital data being relied is the genuine article.
For many commercial purposes the owner of a digital image or audio file has an interest in being able to ascertain whether the image or file has been copied or altered. For example, a television or radio station would generally want to be in a position to prove the genuineness of a data file if the content or accuracy of such file is challenged. An entertainer who has a digital recording of a performance made with a handheld communications device has an interest in assuring that the recording is not copied or distributed. In U.S. Pat. No. 6,628,801, entitled IMAGE MODIFICATION WITH PIXEL MODIFICATION, to Robert D. Powell, et al. (Powell), a method and system is described for inseparably embedding signatures within a visual image so that it persists throughout any image transformation.
In certain areas of interest, such as digital data used as evidence in a legal proceeding, a system or method for the authentication of captured digital data is needed. Powell does not provide this level of authentication. It is also desirable that a useful level of authentication for digital data be available for use with a mobile communications device. This would be particularly useful because mobile communications devices, such as mobile phones and personal digital assistants, are a constant companion for a large percentage of the population.
Mobile phones, as well as other mobile communications devices, have become multi-functional. In addition to being used for speech communications, mobile phones are being equipped with applications that provide SMS or MMS based messaging, e-mail and fax services. They are also routinely equipped with a recording apparatus for capturing dialog or to take speech notes as well as a digital camera for taking still photos and moving pictures in short video clips. However, thus far no method or device is known to authenticate digital data captured by a mobile communications device.
Accordingly, what is needed in the art is a new method and device to authenticate digital data, particular digital data captured by means of a mobile communications device such as a mobile phone.